Effects of Feed Additives and Mixed Eimeria Species Infection on Intestinal Microbial Ecology of Broilers

Evaluation of digestive microbial ecology is necessary to understand effects of growth-promoting feed. In the current study, the dynamics of intestinal microbial communities (MC) were examined in broilers fed diets supplemented with a combination of antibiotic (bacitracin methylene disalicylate) and ionophore (Coban 60), and diets containing 1 of 2 essential oil (EO) blends, Crina Poultry (CP) and Crina Alternate (CA). Five treatments were analyzed: 1) unmedicated uninfected control; 2) unmedicated infected control; 3) feed additives monensin (bacitracin methylene disalicylate) + monensin (Coban 60; AI); 4) EO blend CP; and 5) EO blend CA. Additives were mixed into a basal feed mixture, and EO were adjusted to 100 ppm. Chicks were infected by oral gavage at 19 d of age with Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Duodenal, ileal, and cecal samples were taken from 12 birds per treatment just before and 7 d after challenge; 2 samples each were pooled to give a final number of 6 samples total; and all pooled samples were frozen until used for DNA extraction. Denaturing gradient gel electrophoresis was used to examine PCR-amplified fragments of the bacterial 16S ribosomal DNA variable region. Results are presented as percentages of similarity coefficients (SC). Dendrograms of PCR amplicon or band patterns indicated MC differences due to intestinal location, feed additives, and cocci challenge. Essential oil blends CP and CA affected MC in all gut sections. Each EO had different effects over MC, and they differed in most instances from the AI group. The cocci challenge caused drastic MC population shifts in duodenal, ileal, and cecal sections (36.7, 55.4, and 36.2% SC, respectively). Diets supplemented with CP supported higher SC between pre- and postchallenge MC (89.9, 83.3, and 76.4%) than AI (81.8., 57.4, and 60.0%). We concluded that mixed coccidia challenge caused drastic shifts in MC. These EO blends modulated MC better than AI, avoiding drastic shifts after a mixed challenge

Intestinal Microbial Ecology of Broilers Vaccinated and Challenged With Mixed Eimeria Species, and Supplemented with Essential Oil Blends

Intestinal microbiota is an important component in the development of defense mechanisms in the gut mucosa. This project determined the dynamics of intestinal microbial communities (MC) of broilers vaccinated at first day of age with live oocysts of Eimeria species and fed diets supplemented with 2 specific essential oil (EO) blends, Crina Poultry (CP) and Crina Alternate (CA). Five treatments were analyzed: 1) unmedicated-uninfected (UU) control; 2) unmedicated-infected (UI) control; 3) vaccinated with Advent cocci-vaccine and without feed additive (COV) supplements; 4) vaccinated with Advent and supplemented with CP; and 5) vaccinated with Advent and supplemented with CA. The EO blends were added at 100 ppm to the same basal diets. Chicks were gavage-infected at 19 d of age with Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Duodenal, ileal, and cecal samples were taken from 12 birds per treatment just before the infection and 7 d after the challenge, pooled in 6 samples, and frozen. Denaturing gradient gel electrophoresis was used to examine PCR-amplified fragments of the bacterial 16S ribosomal DNA variable region. Results are presented as percentages of similarity coefficients (SC). Dendrograms of amplicon patterns indicated MC differences due to intestinal location, feed additives, and cocci infection. The EO blends CP and CA did affect MC in all gut sections. The cocci-infection caused drastic MC population shifts in duodenal, ileal, and cecal sections (36.7, 55.4, and 36.2% SC, respectively). The CP-supplemented birds had higher SC between pre- and postchallenge MC in duodenal and ileal (73.3, 81.8%) than COV (66.4, 66.5%). However, COV broilers had the smallest changes in cecal MC after infection (79.5% SC). We concluded that cocci-vaccination causes small changes in intestinal MC, but challenge causes drastic shifts. The EO blend supplementation modulates MC in cocci-vaccinated broilers, avoiding drastic shifts after a mixed coccidia infection. Correlations between MC dynamics and host responses are discussed

Responses of Coccidia-Vaccinated Broilers to Essential Oil Blends Supplementation up to Forty-Nine Days of Age

Coccidiosis control may become a greater problem as the use of growth-promoting antibiotics (GPA) and ionophores declines. Vaccination with live oocysts may turn into a popular alternative to the use of coccidiostats in broilers, although cocci vaccination is frequently linked to temporary lower performance in young flocks. This experiment evaluates the dietary supplementation of 2 specific essential oil (EO) blends (Crina Poultry and Crina Alternate), either as alternatives to GPA and ionophores (BMD + Coban) or as feed additives that help to improve the performance of cocci-vaccinated broilers. Live performance and lesion scores were observed. These 2 specific EO blends differ in their efficacy to promote growth. Chickens that were not cocci vaccinated and were fed Crina Poultry had better feed conversion ratio (FCR) than the unmedicated control treatment in the starter period. The same EO improved FCR in cocci-vaccinated birds in the finisher period in comparison to the negative control group, but those responses were not significantly different from other treatments or significant at 49 d of age. No significant differences were observed in lesion scores at 37 d. Diets supplemented with a GPA-ionophore combination consistently supported the best BW gain and FCR in each period and the entire grow-out period. No significant beneficial or deleterious effects on live performance were observed due to these specific EO blends in cocci-vaccinated broilers

Ecología general

Documento PDF, 43 páginasGuía de estudio para el curso Ecología general, código 0869, que imparte la cátedra de ecología y educación ambiental de la UNED.Universidad Estatal a Distancia de Costa Ric

Effect of Electrolyte Balance in Low-Protein Diets on Broiler Performance and Tibial Dyschondroplasia Incidence

A proper dietary electrolyte balance (DEB) is essential to ensure an optimum acid-base equilibrium and broiler performance. In low-CP diets, this balance can be affected by reduction of soybean meal and inclusion of high levels of synthetic amino acids. Although, some studies have related low-protein diets supplemented with amino acids and DEB, these relations are not well explained, because some research demonstrates confusion about the deficiency and balance of nutrients. The objective of these experiments was to evaluate the DEB effects of diets with low levels of protein supplemented with amino acids on broiler performance and bone development. Results indicated that DEB and CP content influenced broiler chick performance in the starter and growing periods. There was no significant effect due to the interaction between DEB and CP content for tibial dyschondroplasia incidence (TD) or in bone breaking resistance during the growing period of either experiment. The incidence of TD was reduced with 253 mEq/kg DEB in the starter period

[Rafael Vázquez] [Material gráfico]: [(Director del Hotel Reconquista)]

Contiene fotografías pertenecientes al archivo fotográfico del diario "Región", publicadas hacia 1981Algunas fotos no indican autoría; el resto firmadas por Foto E. Gar (Oviedo), Astra (Oviedo

[Manifestaciones contra el terrorismo] [Material gráfico]

Contiene fotografías pertenecientes al archivo fotográfico del diario "Región", publicadas hacia 1981Algunas fotos no indican autoría, el resto por Foto Astra (Oviedo), Foto E. Gar (Oviedo

Dosimetry of large electron beam fields and treatment protocol for mycosis fungoides using the total skin irradiation technique

Introducción: La terapia total de piel con haz de electrones (TSEBT) es una técnica usada en el tratamiento de enfermedades superficiales de piel tales como linfomas cutáneos. Aunque su efectividad ha sido demostrada a través de varios estudios clínicos en estadios avanzados de la micosis fungoide, no es una técnica disponible en muchos centros de cáncer en México debido a que se requieren campos grandes de electrones para cubrir un cuerpo entero. Objetivo: Para obtener campos grandes de electrones para TSEBT, las distancias convencionales de tratamiento no son suficientes. Esto trae la necesidad de una caracterización y calibración especial del haz de electrones a distancias de 500 cm o más y la necesidad de crear un protocolo de tratamiento para TSEBT en nuestro país. Materiales y métodos: Para la puesta en marcha de esta técnica fue seleccionado el acelerador lineal ELEKTA SYNERGY, con una energía de 6 MeV a una distancia fuente-superficie (SSD) de 500 cm, en modo de alta tasa de dosis (1,000 UM = 100 Gy), usando un cono aplicador de 40 × 40 cm2 y el ángulo de gantry de 90◦, obteniendo un campo grande de electrones de 200 × 100 cm2 (área útil). La calibración de rutina fue realizada a una profundidad de referencia (Zref) de 1.4 cm a una SSD de 100 cm y un cono aplicador de 40 × 40 cm2 usando una cámara de ionización de placas plano-paralelas y un electrómetro (Scandotronix Wellhofer modelo PPC05 FOCUS) y un maniquí de agua. El mismo procedimiento fue realizado para determinar la tasa de dosis absoluta en condiciones de tratamiento (500 cm). Para la caracterización del haz de electrones en términos de porcentaje de dosis a profundidad (PDD) y perfiles de dosis, se utilizó Película Radiocrómica Gafchromic EBT2 (PRC), después de ser calibrada para electrones en un maniquí de agua sólida (Scandotronix Wellhofer) a un Zref = 1.4 cm de profundidad a una Distancia Fuente Isocentro SAD de 100 cm y de 500 cm, para obtener la ecuación de la dosis en respuesta de la densidad óptica. La PDD fue obtenida a 0, 1, 1.2, 1.4, 1.5, 2, 3, 4, 5, 6, 7, 8 y 9 cm de profundidad en el maniquí. La distribución espacial de dosis fue obtenida colocando muestras de PRC de 3 × 3 cm2 sobre la pantalla de acrílico que será situada enfrente del paciente (para así obtener la dosis absorbida máxima en piel). Por último, fue propuesto un protocolo de tratamiento. Resultados: La profundidad de dosis máxima (Zref) para electrones fue de 1.4 ± 0.05 cm, de acuerdo con la distribución de dosis espacial relativa y el porcentaje de dosis en profundidad para una SSD de 500 ± 0.5 cm, sobre un área de 200 × 100 cm2. Se graficaron los perfiles del haz tanto horizontal como vertical, mostrando una simetría horizontal de ±0.35%, aplanado horizontal de ±3.62%, simetría vertical de ±2.1% y aplanado vertical de ±14.2%. Conclusiones: Los resultados de los perfiles horizontal y vertical permiten evaluar la simetría y aplanado del haz de electrones. El PDD fue analizado hasta 9 ± 0.05 cm, estableciendo la profundidad de penetración de los electrones, asegurando un tratamiento superficial a la piel.Introduction: Total Skin Electron Beam Therapy (TSEBT) is a technique used in the treatment of superficial skin diseases, such as cutaneous lymphomas. Although it has demonstrated its effectiveness through several clinical studies of the advanced stages of mycosis fungoides, it is not available in most cancer centers in Mexico, because it requires large electron fields in order to cover the entire body. Objective: In order to obtain large electron fields for TSEBT, conventional treatment distances are not sufficient. This has led to the need for an electron beam with special features and calibration at a distance of 500 cm or more, as well as the need to create a treatment protocol to develop the TSEBT programs in Mexico. Materials and methods: The ELEKTA SYNERGY Linear Accelerator was selected with a 6 MeV energy at a Source Skin Distance (SSD) of 500 cm, in high dose rate mode (1,000 MU=100 Gy), using a cone of 40×40 cm2 and the gantry angled to 90◦, obtaining a large electron field of 200×100 cm2 useful area. Routine calibration was performed at a Zref=1.40 cm and an SSD of 100 cm with a 40×40 cm2 cone using a plane-parallel ionization chamber and electrometer (Scandotronix Wellhofer model PPC05 FOCUS) and a water phantom. The same procedure for the absolute dose rate determination was also performed in treatment conditions (500 cm). For the beam characterization in terms of Percentage Depth Dose (PDD) and beam profiles, Radiochromic Gafchromic® EBT2 film (RCF) was used, after being calibrated for electrons in a solid water phantom (Scanditronix Wellhöfer) at a 1.4 cm depth and Source Axis Distance (SAD) of 100 cm and 500 cm, in order to acquire the equation relating the dose response with optical density. PDD was obtained at 0, 1, 1.2, 1.4, 1.5, 2, 3, 4, 5, 6, 7, 8 and 9 cm depths in the phantom. Spatial dose distribution was obtained by placing 3×3 cm2 samples of RCF on an acrylic screen situated in front of the patient (for the purpose of obtaining maximum absorbed dose on the skin). Lastly, a treatment protocol was proposed. Results: An effective maximum dose depth (Zref) for electrons of 1.4±0.05 cm was obtained according to the relative spatial dose distribution and the percentage depth dose for a SSD of 500±0.5 cm, over an area of 200×100 cm2. Horizontal and vertical beam profiles were plotted, showing a horizontal symmetry of ±0.35%, horizontal flatness of ±3.62%, vertical symmetry of ±2.1%, and vertical flatness of ±14.2%. Conclusions: The resulting horizontal and vertical profiles enabled the electron beam symmetry and flatness to be assessed. PDD was analyzed up to a 9±0.05 cm, establishing the electron depth penetration to ensure treatment of the skin surface

[Luis Arrones] [Material gráfico]: [(periodista)]

Contiene fotografías pertenecientes al archivo fotográfico del diario "Región", publicadas entre 1978 y 1981Algunas fotos no indican autoría; el resto firmadas por Foto E. Gar (Oviedo), Astra (Oviedo